Dross compression apparatus are commonly used to recover non-ferrous metals, particularly aluminum, from dross which has been skimmed from a furnace. Aluminum dross is a combination of aluminum metal and aluminum oxides, as well as other possible components such as various oxides, nitrates and carbides. Aluminum dross is a by-product of an aluminum melting operation. Generally the dross floats on top of the molten aluminum metal in the furnace. Aluminum dross may contain anywhere from ten percent to ninety percent aluminum depending on the particular processing technique and the type of furnace. Therefore, the dross in an aluminum melting operation includes a significant amount of aluminum metal which is considered a valuable resource to be recovered.
A factor to consider during the cooling of aluminum dross, with or without the recovery of aluminum, is thermiting of the dross. Thermiting, or thermite reaction, of the dross is exothermic oxidation of aluminum metal in the dross.